Catheters are used for many medical purposes. The present invention is not directed to a specific type of catheter, but rather types of balloons and methods of making said balloons. The balloons may be used for a variety procedures, such as, but not limited to, plain old balloon angioplasty (POBA), stent delivery, peripheral catheter procedures.
Examples of catheters and procedures are addressed below for the sake of background.
In typical PTA or PTCA procedures, a guiding catheter is percutaneously introduced into the cardiovascular system of a patient and advanced through the aorta until the distal end is in the desired (coronary) artery. Using fluoroscopy, a guide wire is then advanced through the guiding catheter and across the site to be treated in the coronary artery. An over the wire (OTW) balloon catheter is advanced over the guide wire to the treatment site. The balloon is then expanded to reopen the artery. The OTW catheter may have a guide wire lumen which is as long as the catheter or it may be a rapid exchange catheter wherein the guide wire lumen is substantially shorter than the catheter. Alternatively, a fixed wire balloon may be used. This device features a guide wire which is affixed to the catheter and cannot be removed.
To help prevent arterial closure, repair dissection, or prevent restenosis, a physician can implant an intravascular prosthesis, or a stent, for maintaining vascular patency inside an artery or other vessel at the lesion.
Stents are also used for a variety of other purposes including maintaining the patency of any physiological conduit including arteries, veins, vessels, the biliary tree, the urinary tract, the alimentary tract, the tracheobronchial tree, the genitourinary system, and the cerebral aqueduct.
The stent may either be self-expanding or balloon expandable. For the latter type, the stent is often delivered on a balloon and the balloon is used to expand the stent. The self-expanding stents may be made of shape memory materials such as nitinol or constructed of conventional metals but of a design which exhibits self expansion characteristics.
A balloon may be used to widen a vessel into which the catheter is inserted by dilating the blocked vessel, such as in an angioplasty procedure. The catheter may also be used to deliver a medical device, such as a stent, into a body lumen. Some examples of stent delivery balloons are disclosed in U.S. Pat. Nos. 5,702,418, 5,968,069 and 5,797,877, the entire contents of these patents are hereby incorporated by reference.
In these and other medical device delivery applications, radial expansion of a balloon may be used to expand or inflate a stent at a desired positioned within the body. Using a balloon equipped catheter to deliver a stent often requires precise positioning of the balloon and stent as well as a balloon with accurate and predictable expansion properties. The present invention aids in positioning the balloon and stent in the targeted areas with enhanced precision.
Currently, a specific concern physicians have with regard to the difficulty in delivering a stent to the targeted site is vessel straitening. This phenomenon is a result of rigidness built up due to the overlapping of the stent, balloon and typically the inner shaft. To reduce this rigidness, flexible stents have been produced. The present invention, in one aspect, seeks to provide balloons which address this problem, among others.
All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
Without limiting the scope of the invention a brief summary of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims.